“This is my house. I have to defend it,”, the protagonist of Home Alone named Kevin McCallister said firmly. But in the case of Nipponaphis monzeni (Japanese aphids), they literally sacrifice themselves to protect their home. With the intent to fix the holes on their nest, they suicidally erupt as it plasters its bodily fluids on the holes.

Each of these aphids is a white bead, just half a millimeter across. In large numbers, they can compel Japanese trees to form large, hollow spheres called galls—roomy mansions in which hundreds or thousands of them can live. Like ants, bees, and termites, aphids divide their labor: Adults reproduce, while immature nymphs act as both workers and soldiers. If moth caterpillars tunnel their way into the galls, the nymphs stab these intruders to death, using the sharp mouthparts that they normally use to suck sap from trees. That deals with the caterpillar, but what about the huge hole that it leaves in the gall?

The aphid’s solution, discovered in 2003, is dramatic. Dozens or hundreds of the young soldiers will gather around a hole and discharge fluid from a pair of tubes on their backsides. This isn’t a gentle leak but a violent eruption, which drains the nymphs so thoroughly that they shrivel down to just a third of their initial volume. As they dry and die, they also use their legs to mix the fluids over the holes. These harden within an hour, sealing the gap and sometimes entombing the suicide plasterers.